1370. ] MELLO-—TIDESWELL-DALE CLAY-BED. 701 
causes of the glaciation or ice-markings of Europe. Nature never 
works by one means alone, but accomplishes her ends by many 
agents, all working, each in due proportion, towards the same end. 
So in these, glaciers have accomplished much, but bergs and sea- 
ice have also done their part in forming the glacier-remains of 
Britain and other portions of the world. The fault of all the theorists 
is to suppose that the means they are advocating—eglaciers, bergs, or 
sea-ice—alone accomplished the end in question. If any one can 
give me a better explanation, then I will gladly give up my own. 
Only if my theory is rejected then my facts must be accounted for, 
and it must be shown how this great deposit of clay, which, as the 
laws of nature are constant, must have been forming in the glacial 
epoch, is to be accounted for. There are difficulties in the way ; 
but as the best theory is the one which explains the greatest 
amount of appearances most reasonably, and as we can only 
reason regarding the past from what we see going on at present, 
I humbly submit there is some degree of truth (at least) in the 
theory I have ventured to submit. 
10. On an AtreRED Ciay-BeEp and Section in Tiprswett Dare, 
DerrpysHirE. By Rey. J. M. Mutto, M.A., F.G.8., &e. 
Tue object of my present communication is to call attention to an 
interesting section that has lately been exposed in a quarry on the 
eastern side of Tideswell Dale in Derbyshire. The locality is ex- 
actly pointed out by the words “ Tideswell Dale” in the Ordnance 
Map No. 81,8.E. At this spot it will be seen, by a reference to 
the map of the Geological Survey, that an outcrop of toadstone occurs. 
Another outcrop of toadstone is also exposed by the railway-cutting 
on the right bank of the Wye, opposite Litton Mill ; this rock is fully 
described in the recently published memoir of the Geological Survey 
relating to this county. Above this are found thinly-bedded lime- 
stones; whilst lower down the river the toadstone is wanting, and a | 
considerable thickness of fossiliferous limestone occurs with “thin 
lenticular partings of shale and red clay.” At the bottom of Miller’s 
Dale a toadstone, capped by about 150 feet of limestone, is seen 
running along the roadside on the left bank of the river; this bed 
up into islands to produce any large bergs. Between the north-east point of 
Spitzbergen and Greenland there are no icebergs until we reach the Greenland 
coast, where a few of inconsiderable size are found, no doubt formed in some of 
the East Greenland fjords. Vide Chydenius, ‘Svenska Expeditionen til Spits- 
bergen, ar 1861, under ledning af Otto Torell,’ &c., 1865, for many valuable 
details on this subject; and some interesting notes by Mr. James Lamont on 
Spitzbergen in the ‘Quart. Journ. Geol. Soc.’ (1860), vol. xvi. pp. 150 & 428. 
Prof. Torell, of Lund, is at present engaged on this subject; and from his re- 
searches much new light may be expected to be thrown on the glacial remains 
of Scandinavia, observations regarding which, by many eminent Scandinavian 
naturalists, have greatly elucidated the subject. Without being invidious, I 
may cite Sars’s ‘ Jagttagelser over den Glaciale Formation’ (Universitets Pro- 
gram, Christiania, 1860) as being of much value to English students of glacial 
clays. 
